Turing Switches – Turing machines for all-optical Internet routing

This is technical report outlining an idea for basic long term research into the architectures for programmable all-optical Internet routers. We are revisiting some of the fundamental tenets of computer science to carry out this work, and so it is necessarily highly speculative. Currently, the processing elements in all-electronic routers are typically fairly conventional von-Neumann architecture computers with processors that have large, complex instruction sets (even RISC is relatively complex compared with the actual requirements for packet processing) and Random Access Memory. As the need for speed increases, first this architecture (see Nick McKeown’s excellent talk in reference [6]), and then the classical computing hardware components, and finally, electronics cease to be able to keep up. At this time, optical device technology is making great strides, and we see the availability of gates, as well as a plethora of invention in providing buffering mechanisms. However, a critical problem we foresee is the ability to re-program devices for different packet processing functions such as classification and scheduling. This proposal is aimed at researching one direction for adding optical domain programmability. 1 Scientific and Technological Rationale and Relevance 1.1 Purpose Turing Switching The goal of this project is to revisit basic computer science and the architectural design of computers for switching we refer to our approach as Turing Switching, as we will argue that by analogy with the original Turing Machine, a packet switch control system need not be a von Neumann architecture, or anything closely resembling it. We wish to provide a programmable optical packet switch, which has the flexibility of a software system, and the performance of an optical system. This is against current trends towards circuit (or at least label switching and wavelength or wave-band) switching. The motivation is to retain advantages of: This term was recently unearthed by Tom Scott and reported in a personal communication with the proposer.